1. Field of the Invention
This invention relates generally to an automatic paper splicing control device, and more specifically to an automatic paper splicing control device for automatically splicing a travelling paper with a roll paper while the papers continuously travel. The travelling paper is spliced with the roll paper in a good condition by controlling the splice so that the travelling paper is in contact with the surface of the roll paper when the adhesive coated area of the roll paper surface reaches a predetermined position.
2. Description of the Prior Art
In a rotary press, for example, a roll is prepared in advance so that a part of its surface is coated with adhesive. The roll paper is then spliced with a travelling paper immediately before the travelling paper is used up, thus enabling the printing paper to be fed continuously. As shown in FIG. 1, a roll paper 2 has part of its surface coated with adhesive. The roll paper is disposed at a predetermined position with respect to a travelling paper 1 running in the direction as shown by arror a. The roll paper is rotated in the direction b so that the surface of the roll paper 2 maintains approximately the same speed as the travelling speed of the travelling paper 1. Immediately before the travelling paper 1 is used up, the travelling paper 1 is depressed onto the surface of the roll paper by operating a depressing means such as the brush 4, to cause the roll paper to be spliced with the travelling paper 1 by means of the adhesive 3. At that moment, a cutter 5 is operated to cut the travelling paper 1 at a predetermined position following the spliced portion of the travelling paper 1 and the roll paper 2.
In this type of paper splicing device, the brush 4 comes in contact with the travelling paper 1 to depress the travelling paper 1 onto the roll paper just at the moment when the adhesive coated area of the roll paper 2 arrives at the position to be spliced. At that moment, however, the travelling paper 1 tends to slip off the adhesive coated area, resulting in a splicing failure.
Taking this drawback into consideration, a device has been devised in which control is effected so that the travelling paper 1 is depressed onto the roll paper by means of the brush 4 at a time To, before the adhesive coated area arrives at the position to be spliced. The travelling paper 1 and the roll paper 2 are then spliced with each other by the brush 4 which has already arrived at the position to be spliced even before the adhesive coated area arrives at the position to be spliced. That is, assume that the time for the brush 4 to move to the position to be spliced is T. A detecting means for detecting the leading edge of the adhesive 3 is disposed at a predetermined angular position at which the leading edge of the adhesive 3 can be detected at time (T+To) before the adhesive 3 arrives at the position to be spliced. When the detecting means detects the adhesive 3, the detecting means issues a command for starting the operation. However, the proper splicing may not be effected in this type of paper splicing control device partly because the diameter of the roll paper 2 is not constant, and partly because the surface speed of the roll paper 2 varies with the individual type of roll paper.